Massive essential project in the heart of Stockholm
The Slussen area in central Stockholm is named after the locks between Lake Mälaren and the Baltic Sea. The entire Slussen area is currently undergoing a major redevelopment, including rebuilding the lock and sluice system as well as the road and rail infrastructure. The €1.3 billion project is expected to be complete in 2025.
The New Slussen project is vital for the entire Stockholm region around Lake Mälaren. It will both protect key infrastructure from flooding, as a result of sea level rise caused by climate change, and secure the drinking water basin for around two million people. The Slussen redevelopment includes drainage channels and higher flood gates to cope with sea level rise and the greater risk of flooding posed by climate change in the coming decades.
The Slussen stainless steel sluice gates are among the largest of their type in the world and are designed to resist corrosion in the brackish water environment over a 100-year lifespan. As the gates cannot be removed once they are in operation, their strength and corrosion resistance are of great importance. They simply cannot be allowed to fail during their long lifespan.
Premium high strength and corrosion resistant stainless steel fasteners
Skanska, the Swedish construction company acting as the general contractor on the project for the customer Stockholm Stad, ordered approximately 15,000 BUMAX® fasteners for the project during 2020 to be used on the Slussen sluice hatches. The fasteners specified were a mixture of BUMAX® 88 (A4/316L) and also BUMAX® SDX 109 (Super Duplex), which provided a higher level of both strength and corrosion resistance. This solution catered for conditions posed by brackish water from Lake Mälaren and also the higher salinity of the sea water from the Baltic Sea.
“BUMAX was able to provide us with stainless steel fasteners that fully met our high strength and excellent corrosion resistance requirements for the Slussen project,” says Bob Hamberg, Purchase Manager at Skanska Sweden.
Special testing for large fasteners
Around 90 different types of BUMAX fasteners were ordered for the Slussen project. The largest of these fasteners were BUMAX® SDX threaded rods M48x1225 and M36x1125, in class 80.
Due to the size and strength of these largest rods, BUMAX collaborated with RISE (the Research Institute of Sweden) to utilize specialist testing equipment, in order to test the mechanical strength of the fasteners. These tests showed that the rods could reach loads of 886kN (over 90 tons) prior to yield and 1,221kN (over 124 tons) on fracture.
“BUMAX premium fasteners are simply the best for extremely demanding projects like the Slussen project,” said Lars Holm, Managing Director, BUMAX. “We are obviously happy to be selected as a supplier by such a distinguished construction companies for such an essential infrastructure project, and we look forward to providing fasteners to many similar projects around the world in the coming years.”
PHOTO CAPTION: The Slussen construction project in Stockholm, July 2020. ©Holger Ellgaard.